JPH10311236A - Suction air quantity control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To optimize a suction air quantity by a suction air quantity control device at vehicle deceleration time, and prevent the deterioration of operability by correcting the suction air quantity so as to increase it from a first suction air correction quantity on which an operation is performed when a throttle valve is fully closed and a second suction air correction quantity on which an operation is performed at engine speed reduction time. SOLUTION: When an internal combustion engine 1 is operated, in a control unit 10, an operation is performed on a first suction air correction quantity to increase a suction air quantity in a moment when detecting a fully closed condition where a throttle valve 7 transfers to an almost fully closed condition from an opening condition. An operation is also performed on a second suction air correction quantity to increase the suction air quantity in a moment when judged that an engine speed detected from output of a crank angle sensor 14 is reduced to a prescribed engine speed or less from the prescribed engine speed or more. A bypass air control valve 10 interposed in a bypass air passage 10 to bypass the throttle valve 7 is controlled so as to increase the suction air quantity according to these first and second suction air correction quantities.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake air amount control device for controlling an intake air amount mainly during idling of an internal combustion engine, and controls an intake air amount during idling operation or deceleration operation, that is, idling rotation. It relates to a device for controlling the number.

[0002]

2. Description of the Related Art As a conventional idle speed control device for an internal combustion engine, a target speed is determined in accordance with an engine warm-up state such as an engine temperature, and intake air is set so that the actual speed matches the target speed. Devices for feedback control of quantities are known. Also, in an intake air amount control device that switches and controls feedback control and open loop control without feedback according to various operating conditions of the engine, the throttle valve is fully closed while the vehicle is running at a reduced speed and open loop control. A method of calculating the correction amount of the intake air amount according to the engine speed at that moment at the moment when the state is reached, increasing the intake air amount by the correction amount, and thereafter gradually decreasing the correction amount, for example, It is already known from JP-B-62-40536.

[0003]

In such an apparatus, a sudden change in the amount of intake air supplied when the engine is idling (racing) or when the load shifts from a throttle-depressed state to a throttle-opened engine brake state. At the time, the oil rises due to a sudden rise in the negative pressure in the intake pipe, and afterburn occurs.

In addition, due to a delay in the feedback control, the exhaust gas purifying performance is temporarily reduced, the engine speed is abnormal,
Alternatively, the possibility of causing an engine stall (so-called engine stall) increases, which adversely affects the driving feeling of the vehicle.

As a method for solving such a problem,
Conventionally, a correction amount of the intake air amount is defined according to the engine speed at the moment when the throttle valve of the engine changes to the fully closed state, and the intake air amount is increased by the correction amount.

However, even in such a conventional method, for example, when the flow path volume from the throttle valve to the cylinder is large due to the structure of the engine, for example, a supercharger is provided downstream of the throttle valve and the flow path Is longer, the behavior of the engine speed corresponding to the change of the throttle valve becomes slower than that of the smaller flow path volume because the flow path volume increases.

Further, in such an engine, the method of increasing the intake air correction amount in accordance with the engine speed at the time of the deceleration determination without taking into account the engine operation state before the deceleration determination as in the above-described conventional example, There has been a problem that the behavior of the engine speed after the intake air amount is increased becomes unstable, and in the worst case, engine stall occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The present invention has been made to optimize the intake air amount by an intake air amount control device at the time of deceleration of a vehicle, to reduce the engine speed and to idle the vehicle. It is an object of the present invention to obtain an intake air amount control device for an internal combustion engine that does not cause a feeling.

[0009]

According to a first aspect of the present invention, there is provided an intake air amount control device for an internal combustion engine, which controls an intake air amount of the internal combustion engine, and a throttle valve of the internal combustion engine. A full-closed detecting means for detecting that the engine has shifted from the open state to the substantially fully closed state, a rotational speed detecting means for detecting a rotational speed of the internal combustion engine, and an engine rotational speed detected by the rotational speed detecting means. Rotation speed deceleration determining means for determining that the rotation speed has been reduced from the rotation speed or more to the predetermined rotation speed or less,
First intake air correction amount calculating means for calculating a first intake air correction amount for increasing the intake air amount at the moment when the throttle valve is detected to be substantially fully closed by the fully closed detection means; Calculating a second intake air correction amount for increasing the intake air amount at a moment when the rotation speed deceleration detecting means determines that the rotation speed has been reduced from the predetermined rotation speed or more to the predetermined rotation speed or less. An intake air correction amount calculating means, and an intake air amount increasing means for increasing an intake air amount according to the intake air correction amount obtained by the first and second intake air correction amount calculating means.

In the intake air amount control device for an internal combustion engine according to a second aspect of the present invention, the second intake air correction amount calculating means detects that the throttle valve is substantially fully closed by the fully closed detection means. From the moment, the air corresponding to the maximum value of the rotational speed detected by the rotational speed detecting means until the rotational speed deceleration determining means determines that the engine rotational speed has decreased from the predetermined rotational speed or more to the predetermined rotational speed or less. The correction amount is calculated.

According to a third aspect of the present invention, in the intake air amount control apparatus for an internal combustion engine, the second intake air correction amount calculating means calculates a deviation of the rotational speed detected by the rotational speed detecting means at each predetermined timing. When the rotation speed deceleration determination means determines that the engine rotation speed has been reduced from a predetermined rotation speed or higher to a predetermined rotation speed or lower, an air correction amount corresponding to the stored rotation speed deviation is calculated. Is what you do.

According to a fourth aspect of the present invention, there is provided the intake air amount control device for an internal combustion engine, wherein the second intake air correction amount calculating means starts from the moment when the throttle valve is detected to be substantially fully closed by the fully closed detection means. Is an operation for calculating an air correction amount corresponding to a time period until the rotation speed reduction determining means determines that the engine rotation speed has been reduced from a predetermined rotation speed or more to a predetermined rotation speed or less.

According to a fifth aspect of the present invention, there is provided the intake air amount control apparatus for an internal combustion engine, wherein the first intake air correction amount calculation is performed at the moment when the full-close detecting means detects that the throttle valve is substantially fully closed. After the means sets the intake air correction amount to a first predetermined value, the first predetermined value is held for a first predetermined period, and then reduced to zero by a first predetermined reduction amount at each first predetermined timing. It is to let.

According to a sixth aspect of the present invention, in the internal combustion engine intake air amount control device, the first intake air correction amount is set at the moment when the throttle valve is detected to be substantially fully closed by the fully closed detection means. The calculating means changes at least one of the first predetermined value, the first predetermined period, the first predetermined timing, and the first predetermined decrease amount according to the rotation speed detected by the rotation speed detection means. Things.

According to a seventh aspect of the present invention, in the intake air amount control apparatus for an internal combustion engine, the second intake air correction amount calculating means includes:
At the moment when the rotation speed deceleration detecting means determines that the rotation speed has been reduced from the predetermined rotation speed or more to the predetermined rotation speed or less, the intake air correction amount is set to a second predetermined value, and the second predetermined value is set. After holding for a second predetermined period, the second predetermined reduction amount is reduced to zero at every second predetermined timing.

An intake air amount control apparatus for an internal combustion engine according to the invention of claim 8 is characterized in that at the moment when it is determined that the rotation speed from the rotation speed deceleration detecting means has decreased from a predetermined rotation speed or more to a predetermined rotation speed or less, The second intake air correction amount calculating means detects at least one of the second predetermined value, a second predetermined period, a second predetermined timing, and a second predetermined decrease amount from the rotation speed detecting means. It is changed in accordance with the number of rotations performed.

According to a ninth aspect of the present invention, there is provided an internal-combustion-engine intake air amount control device, further comprising: a load operation determining unit that determines whether the internal combustion engine is in a no-load operation or a load operation.
The first and second intake air correction amount calculating means changes at least one of a first and second predetermined value, a predetermined period, a predetermined timing, and a predetermined decrease amount based on a determination result from the load operation determining means. It is.

According to a tenth aspect of the present invention, in the intake air amount control apparatus for an internal combustion engine, the load operation determining means includes a compressor operation signal of an air conditioner which is a load driven by the internal combustion engine and an operation signal of a power steering. ,
A signal detection function for detecting an electric load operation signal attached to the vehicle or an operation signal of a generator driven by the internal combustion engine, and a vehicle traveling determination for determining whether the vehicle is traveling or stopped. A first and second predetermined values of the first and second intake air correction amount calculating means, a predetermined period, and a predetermined period based on the detection signal or the vehicle traveling determination result by the vehicle traveling determining function. At least one of the timing and the predetermined decrease amount is changed.

According to a still further aspect of the present invention, there is provided the internal combustion engine intake air amount control device, wherein the vehicle drive determining function of the load drive determining means is such that the vehicle speed is equal to or higher than a predetermined value and the transmission by the transmission. When it is determined that the vehicle is running when the torque transmission between the internal combustion engine and the wheels is detected, the vehicle is determined to be under load operation.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration diagram showing the overall configuration of the internal combustion engine according to the present embodiment. In FIG. 1, 1
Is a well-known four-cycle spark ignition type engine. The combustion air is supplied from an air cleaner 2, an intake pipe 3, a throttle valve 7,
It is mainly sucked through the surge tank 4 and the intake manifold.

The fuel is supplied from a fuel system (not shown) via an injector 5 provided in the intake manifold. The throttle opening θ of the throttle valve 7 is detected by a throttle sensor 8 and a signal corresponding to the throttle opening θ is output. The fully closed throttle valve 7 is detected by the idle switch 9 and outputs an ON / OFF signal.

A bypass air passage 11 that bypasses the throttle valve 7 is connected to the intake pipe 3 at a position above and downstream of the throttle valve 7 of the intake pipe 3. The bypass air passage 11 is provided with a bypass air control valve 10 for controlling an opening cross-sectional area of the bypass air passage 11. The bypass air whose flow rate is controlled by the bypass air control valve 10 is drawn into the engine 1 as combustion air through the bypass air passage 11.

Reference numeral 6 denotes a semiconductor type pressure sensor provided in the surge tank 4 for measuring the amount of air taken into the engine 1, reference numeral 14 denotes a thermistor type water temperature sensor for detecting the cooling water temperature of the engine 1, and reference numeral 15 denotes exhaust gas. Tube, 12 is engine 1
A crank angle sensor that outputs a pulse signal corresponding to the crank angle of 16; a vehicle speed sensor 16 that outputs a pulse signal having a frequency proportional to the rotation speed of the wheel axle; 13 is controlled by a signal from an electronic control unit 19; A spark plug installed to blow sparks for each cylinder of the engine 1, a battery 17 for supplying voltage to the electronic control unit 19, and an ignition 18 for turning on / off the battery voltage supplied to the electronic control unit 19 A key switch 19 is an electronic control unit that controls driving of the engine 1.

The electronic control unit 19 uses the input information from the crank angle sensor 12, the pressure sensor 6, the water temperature sensor 14, the vehicle speed sensor 16 and the like, and uses a known method to obtain the fuel injection amount of the engine 1 and the bypass air. The injector 5 calculates the fuel injection amount and the optimum ignition timing, and injects the fuel for a predetermined time corresponding to the calculated fuel injection amount.
Control of the engine 1 by controlling the bypass air control valve 10 so as to obtain the calculated bypass air amount and the spark plug 13 so as to obtain the calculated optimum ignition timing. .

FIG. 2 is a detailed block diagram of the electronic control unit 19. In the figure, reference numeral 100 denotes a microcomputer, which is a counter 201 for measuring the rotation cycle of the engine 1;
Timer 202 for measuring the driving time of various outputs, A / D converter 203 for converting an analog input signal to a digital signal, input port 204 for inputting a digital signal and transmitting it to CPU 200, RA as a work memory
M205, ROM 206 storing programs shown in the flowcharts shown in FIGS.
An output port 207 for outputting a command signal of the microcomputer 200 and a common bus 208 for interconnecting the components of the microcomputer 100 to exchange data are provided.

Reference numerals 101 to 103 denote sensors 6, 8, 9, and 1, respectively.
First to third input interfaces 104 for inputting signals to the microcomputer 100 from 2, 14, and 16;
Is an output interface circuit that outputs a control signal calculated by the microcomputer 100 to the injector 5, the bypass air control valve 10, and the ignition plug 13,
Reference numeral 5 denotes a first power supply circuit that converts a battery voltage input through the ignition key switch 18 into a constant voltage and supplies the constant voltage to the microcomputer 100.

Here, the first input interface circuit 1
01, the signal from the crank angle sensor 12 is
The waveform is shaped and converted into an interrupt signal and input to the microcomputer 100. Each time this interrupt signal is generated, the CPU of the microcomputer 100
200 reads the value of the counter 201, calculates the cycle of the engine rotation from the difference between the read value and the previously read value, and stores the cycle in the RAM 205.

The second input interface circuit 10
2 is a pressure sensor 6 and a throttle sensor 8,
The analog output signal from the water temperature sensor 14 and the like is removed, and the signal is amplified and output to the A / D converter 203.

The third input interface circuit 103 includes:
The input ON / OFF signal of the idle switch 9 and the like and the level of a pulse signal from the vehicle speed sensor 16 are converted into digital signal levels and output to the input port 204.

The output interface circuit 104 performs processing such as amplification on the drive output input from the output port 207 and outputs the drive output to the injector 5, the bypass air control valve 10, the ignition plug 13, and the like. First power supply circuit 10
Reference numeral 5 denotes a microcomputer which receives a voltage from the battery 17 when the key switch 18 is turned on and converts the voltage into a constant voltage.
Supply to 00. Thereby, the microcomputer 10
0 starts operation. Here, the microcomputer 100 includes intake air amount control means, fully closed detection means, rotation speed detection means, rotation speed deceleration detection means, first and second intake air correction amount calculation means, intake air increase means, load operation Each of the determination means is configured.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. First, after performing initial settings such as the setting of the RAM 205, the timer 202, and the interrupt of the microcomputer 100, the process proceeds to step S301. In step S301, rotation speed data Ne representing the engine rotation speed NE is obtained from the crank angle cycle already detected in the interrupt processing of the crank angle signal from the crank angle sensor 12.

In step S302, the throttle sensor 8
And the like, and the throttle opening value TH indicating the throttle opening θ detected by the pressure sensor 6, the intake pipe pressure value Pb indicating the intake pipe pressure PB detected by the pressure sensor 6, and the like. In step S303, the previously read data (Ne, TH, P
b)), a process other than that described later (control of fuel supply, ignition timing, etc. is performed, although not described in detail) is performed.

In step S304, the control of the bypass air control valve 10, whose details are shown in the flowchart of FIG. 4, is performed based on the previously read data (Ne, the ON / OFF signal of the idle switch 9, the pulse signal of the vehicle speed sensor 16, etc.). Perform the quantity calculation process. After the process of step S304, the process returns to step S301 to repeat the above operation.

Next, a detailed description will be given, with reference to FIG. 4, of the control amount calculation processing of the bypass air control valve 10 in step S304 in FIG. First, in step S401, the basic bypass air amount Q for maintaining the target rotation speed according to the operating state of the engine 1 (such as a warm-up state, details are not described).
BASE is set, and the flow advances to step S402 to determine whether or not the idle switch 9 is ON, that is, whether or not the idle switch 9 is in an idle state.

If it is ON, the process proceeds to step S403, and it is determined whether or not the idle switch 9 was ON when the same process was executed last time. That is, steps S401 and S40
2, the change of the idle switch 9 is determined. If the idle switch 9 is ON last time, that is, if there is no change in the idle state, the process proceeds to step S404.

If the idle switch 9 is OFF in the previous step S403, that is, if it is determined that the idle state has been changed from a state other than the idle state to the idle state, the process proceeds to step S409, and the first stage as the first predetermined value is set. A bypass air correction amount (dashpot amount) QDP and a holding time TDP as a first predetermined period are set. In the present embodiment, the constant value XQDP1 (for example, 12 [l / mi]
n]), XTDP1 (for example, 8, in this embodiment, 25
A down counter of msec is used, and the holding time is 2 [s
ec]). The processing of steps S401 to S409 fulfills the function of the first intake air correction amount calculating means.

Next, at step S410, the engine speed maximum value NeMAX related to the next-stage dashpot amount is set.
Is initialized to the current Ne, and the process proceeds to step S411. In step S404, the current Ne is compared with NeMAX. If the current Ne is larger than NeMAX, the process proceeds to step S405 to update NeMAX.
Proceed to 406. If the current Ne is smaller than NeMAX, the process proceeds to step S406.

In step S406, it is determined whether or not the rotational speed condition is satisfied, that is, whether or not the current Ne is equal to or more than a predetermined value (for example, 1500 [rpm]). In the above case, the process proceeds to step S411. When the condition is not satisfied, the process proceeds to step S407, and it is determined whether or not the rotational speed condition is satisfied last time. If the condition is satisfied, the process proceeds to step S408.

In steps S406 and S407, it is determined that the rotational speed has changed from a predetermined rotational speed to a lower rotational speed. In step S408, a second-stage dashpot amount QDP as a second predetermined value and a holding time TDP as a second predetermined period are set. In the present embodiment, NeMA is performed until the rotation speed changes from a predetermined rotation speed or more to a predetermined rotation speed or less.
Values XQDP2 and XTDP2 corresponding to X are set.
Here, the relationship between NeMAX and XQDP2, XTDP2 is as shown in FIGS. Step S404-
The processing in step S408 fulfills the function of the second intake air correction amount calculating means.

That is, the dashpot amount XQPD2 and the holding time XTDP2 corresponding to the rotational speed maximum value NeMAX from when the idle switch 9 is turned ON until the rotational speed becomes equal to or lower than the predetermined rotational speed are set, and the process proceeds to step S411. . If it is determined in step S407 that the rotational speed condition was not satisfied last time, the process proceeds to step S411.

Next, in step S411, a correction amount Qetc other than the dashpot amount (a feedback amount according to a difference between a target rotation speed and an actual rotation speed, a load correction when an air conditioner is connected, and the like are not described in detail. ), And the process proceeds to step S412. In step S412, the basic bypass air amount QBASE, the dashpot amount QDP, and the other correction amount Qetc are added, and the bypass air amount QISC is added.
, And the process proceeds to step S414.

On the other hand, if it is determined in step S402 that the idle switch 9 is OFF, that is, if it is determined that the idle switch 9 is not idle, the flow proceeds to step S414, and the flow proceeds to step S414 with the bypass air amount QSSC as the basic bypass air amount QBASE. . Further, in the present embodiment, since the bypass air control valve 10 of the stepper motor type is used, in step S414, the bypass air amount QIS
In order to obtain the control amount of the bypass air control valve 10 corresponding to C, that is, the target motor position P, Q shown in FIG.
The target motor position P is obtained from the ISC map, and the control amount calculation processing of the bypass air control valve 10 ends.

FIG. 10 shows a drive processing routine of the bypass air control valve 10 according to the control amount of the bypass air control valve 10 calculated in the above-mentioned routine, that is, the target motor position P, which is executed, for example, every 10 msec. You.
First, in step S1001, the actual position of the bypass air control valve 10 is read, and the flow advances to step S1002.

In step S1002, a comparison is made between the target position P calculated by the control amount calculation routine of the bypass air control valve 10 and the actual position. End the routine. If it is determined in step S1002 that the target position P is smaller than the actual position, the process proceeds to step S1003, where the bypass air control valve 10
Is driven to the closing side by one step to end the bypass air control valve driving routine.

If it is determined in step S1002 that the target position P is larger than the actual position, the flow advances to step S1004 to drive the bypass air control valve 10 by one step to the open side to end the air control valve driving routine. As described above, the bypass air control valve 10 is driven to open or close by one step each time the bypass air control valve driving routine is executed. And step S
If it is determined in 1002 that the target position P is equal to the actual position, the bypass air control valve driving routine ends.

FIG. 5 shows a timer processing routine for performing processing of a timer and the like (not described in detail) used in the above-described various processing, and is executed, for example, every 25 msec which is the first and second predetermined timings. Is what is done. First,
In step S501, the timer TDP (holding time 2
c: 2000), 1 is subtracted every 25 msec, and the process proceeds to step S502 to compare with zero. If it is determined that the value is equal to or less than zero, the process proceeds to step S503, where zero is substituted into the timer TDP, and the timer process ends. Thereby, the first
Alternatively, the second intake air correction amount (XQDP1, XQDP
The retention elapsed time in 2) is determined.

If it is determined in step S502 that the timer TDP is equal to or greater than zero, the timer processing routine is terminated, and the timer TDP is executed in the next timer processing routine.
1 is subtracted from it. Thus, the processing of the timer TDP is performed in this processing routine.

Through this timer processing routine, the intake air correction amounts XQDP1, XQDP1,
The timer TDP, which is the first and second predetermined periods that hold (set in steps S409 and S408 in FIG. 4), counts down.

FIG. 6 shows the bypass air control valve 10.
This is a routine for performing a subtraction process of each dashpot amount which is the first or second intake air correction amount set in the control amount calculation processing routine of this embodiment. In the present embodiment, at the first or second predetermined timing, This is a routine that is executed every 500 msec.

First, in step S601, it is determined whether or not the timer TDP is zero from the timer processing routine.
That is, it is determined whether or not the holding time has elapsed. If the timer TDP is not zero, the dashpot amount subtraction routine is terminated as it is, and the next dashpot amount subtraction routine waits until the timer TDP becomes zero. Step S6
If the timer TDP is zero at 01, the process proceeds to step S602, and the dashpot amount QDP is reduced by a predetermined value that is the first or second predetermined reduction amount (3 [l / mi in the present embodiment).
n]), and proceeds to step S603.

In step S603, the dashpot amount QDP is compared with zero. If it is determined that the dashpot amount is equal to or greater than zero, the dashpot amount subtraction routine is terminated. Also, in step S603, the dashpot amount QDP
Is determined to be equal to or less than zero, the process proceeds to step S604, and zero is substituted for the dashpot amount QDP, and the dashpot amount subtraction routine ends. Thereby, the bypass air amount QIS in step S412 (see FIG. 4)
C decreases every 500 msec, and the control amount of the bypass air control valve 10 is reduced to 0 after a predetermined time in step S414.
Can be converged.

FIGS. 11 and 12 are time charts for supplementarily explaining the operation at the time of deceleration of the vehicle according to the above-mentioned flowchart. The throttle valve opening TH with respect to the time axis, the idle switch signal, the engine speed Ne, and the bypass air amount QSIC1 are shown in FIGS. , 2 are shown.

First, FIG. 11 is a time chart when the driver depresses the accelerator from the depressed state to the open state, that is, when the throttle valve 7 is changed from a constant opening degree to a fully closed state.
The dotted line in the behavior of the rotation speed Ne is the rotation speed behavior when the amount of bypass air is not increased. Also, the rotational speed Ne
The solid lines (circle 1) and (circle 2) in the behavior of (1) show the behavior of the rotation speed Ne when the bypass air amount is increased as in the conventional example (circle 1) and the present embodiment (circle 2), respectively. .

Here, the behavior of the rotational speed Ne when the amount of bypass air is not increased is reduced once, and then reaches the target rotational speed (800 rpm). Further, at this time, the negative pressure in the intake pipe rapidly rises, causing oil rise, afterburning, deterioration of exhaust gas, and the like. In order to solve this problem, in the conventional example, at the moment when the throttle valve 7 is fully closed, that is, when the idle switch 9 changes from OFF to ON (time t1), the bypass air amount is changed according to the rotational speed A at that time. The QISC1 is increased as shown in FIG. 11 (circle 1). Therefore, the behavior of the rotation speed Ne changes from the value far exceeding the target rotation speed (800 rpm) to the target rotation speed (800 rpm) along with the decrease amount of the bypass air amount QISC1, as shown in (circle 1) in FIG. Transition to.

However, according to the present embodiment, at time t1 when the throttle valve 7 is fully closed, and at the moment when the rotational speed becomes equal to or lower than the predetermined rotational speed (1500 rpm) (time t2).
11, the bypass air amount QSSC2 is increased as shown in (circle 2), (circle b), and circle c, respectively, and the behavior of the rotation speed Ne is shown in (circle 2) in FIG. Converges to the target rotation speed in a shorter time as compared to ()).

FIG. 12 shows a case where the throttle valve 7 is changed from fully closed to fully opened to fully closed earlier than in FIG.
At time t1, that is, at the moment when the idle switch 9 changes from OFF to ON, in the conventional example, as in FIG. 11, the bypass air amount QI according to the rotational speed A at time t1.
In order to increase SC1 as shown in FIG. 12 (circle 1), as shown in FIG. 12 (circle 1), the rotational speed Ne drops once and then increases the rotational speed in the ± direction around the target rotational speed (800 rpm). It converges to the target rotational speed after a predetermined time while changing.

However, according to the method of the present embodiment, the amount of increase (circle a) of the bypass air amount QISC2 at time t1 is the same as that in FIG. 11, but the rotation speed is the predetermined rotation speed (1500r).
pm) or less (time t2), the amount of increase (circle b) of the bypass air amount QISC2 becomes an amount corresponding to the rotation speed B different from FIG. 11, and the behavior of the rotation speed Ne is shown in FIG.
It converges to the target rotation speed in a short time as shown in (circle 2). As described above, in the conventional example, the bypass air amount QIS is used in both FIGS.
Since only the same correction can be performed for C1, the convergence to the target rotation speed is delayed in FIG. 11, and a phenomenon occurs in which the rotation speed is lower than the target rotation speed in FIG.

The phenomenon shown in FIG. 12 (circle 1) increases as the volume of the flow path from the throttle valve 7 to the cylinder of the engine 1 increases. However, in the present embodiment, since the subsequent convergence to the target rotational speed can be accurately and quickly corrected while suppressing a rise in the negative pressure in the intake pipe, there is no danger of engine stall and the driving feeling is improved.

In the present embodiment, the throttle switch 7 is determined to be fully closed by the idle switch 9. However, the present invention does not limit the fully closed detection means. It may be determined by, for example, the detection value of the throttle opening sensor 8 or by comparing one of the detected values of the intake air amount or the intake pipe pressure with a predetermined value. It may be.

This embodiment describes the operation processing for correcting the change in the intake air amount with respect to the rapid change of the throttle valve 7, and includes the change of the throttle valve 7 from a low opening to a fully closed state. When the change of the throttle valve 7 per unit time is small, the correction of the intake air amount may not be performed.

In this embodiment, a stepper motor type bypass air control valve 10 for controlling the opening cross-sectional area of the bypass air passage 11 is used as the intake air amount control means. It is not limited to the control means. For example, a linear solenoid type bypass air control valve whose flow rate changes in proportion to the input current, or a control valve which controls the air flow rate by the ON / OFF duty ratio of the input current is used. Is also good.

In this embodiment, after the throttle valve 7 is substantially fully closed, the engine speed is increased to a predetermined speed (15 rpm).
When the behavior of the engine speed is detected to be lower than 00 rpm), the engine speed corresponds to the maximum value NeMAX of the engine speed until it is determined that the engine speed tends to decelerate from the predetermined speed to the predetermined speed. Second dashpot quantity QD
After setting P and the second timer value TDP, the second air correction amount Qetc was calculated.

However, the deviation of the engine speed at each predetermined timing is calculated and stored in the RAM 205, and is stored when it is determined that the engine speed tends to decelerate from the predetermined speed to the predetermined speed. RAM 205
The second air correction amount Qetc may be calculated after setting the second dashpot amount QDP and the second timer value TDP in accordance with the deviation.

Alternatively, when it is determined that the rotational speed is in a decelerating tendency, each deviation stored so far in the RAM 205 is read to obtain a moving average value of these deviations, and a second dashpot corresponding to the moving average value is obtained. After setting the amount QDP and the second timer value TDP, the second air correction amount Qetc may be calculated.

Further, after setting the second dashpot quantity QDP and the second timer value TDP corresponding to the time when it is determined that the engine speed has decreased from the predetermined speed to the predetermined speed or less. , The second air correction amount Qetc.

Further, in the present embodiment, the timing for setting the dashpot amount of the second stage is set at a predetermined rotation speed (150 rpm).
However, the present invention does not limit this timing to a predetermined rotation speed, and may be any timing that can correct the intake air amount in advance so that the engine rotation speed does not drop below the target rotation speed. For example, means for setting a target rotation speed according to at least a warm-up state of the engine is provided, and a deviation between the actual rotation speed and the target rotation speed is obtained. The eye dashpot amount may be set.

Embodiment 2 In the first embodiment, the set value and the holding time of the dashpot amount when the throttle valve is fully closed (first stage) are set to constant values XQDP and XTDP irrespective of the engine operating state at that time. And
The constant value is set to be a minimum value that can prevent a sudden rise in the negative pressure in the intake pipe and minimize the influence on the engine speed after the throttle valve is fully closed.

However, in the first embodiment, the set value and the holding time of the dashpot amount when the engine speed decreases (second stage) change according to the deceleration of the engine speed after the throttle valve is fully closed. With such a configuration, when the deceleration of the engine speed is large, such as when decelerating from high-speed rotation, the amount of intake air is corrected in a large amount in a short time.

For this reason, if the intake air amount cannot be corrected in a large amount in a short time due to factors such as the maximum flow rate of the intake air amount control means and the operating speed, the second-stage dashpot amount QDP becomes too small or too small. Occurs, and the convergence of the engine speed to the target speed is deteriorated.

In response to such a phenomenon, the first embodiment described in step S409 of FIG.
The set value QDP and the holding time TD of the dashpot amount of the tier
P may be set to a value corresponding to the engine speed when the throttle valve is fully closed, for example, a value as shown in FIGS.

As a result, the intake air amount corrected when the throttle is fully closed is appropriately increased in accordance with the rotation speed when the throttle is fully closed, and the increased amount, the set value of the second-stage dashpot amount and the holding time By setting less than in the first embodiment, for example, it is possible to set as shown by the broken lines in FIG. 7 (circle a) and FIG. 8 (circle a). Therefore, even when the amount of intake air cannot be corrected in a large amount in a short time, convergence of the engine speed to the target speed can be quickly and accurately performed.

In the present embodiment, the value to be changed according to the rotation speed when the throttle is fully closed is the set value of the first-stage dashpot amount and the holding time, but the present invention sets the value to be changed to the set value. The holding time is not limited to this, and it is sufficient that the intake air amount corrected after the throttle is fully closed can be increased or decreased according to the rotation speed when the throttle is fully closed. For example, the dashpot amount subtraction processing of FIG.
What is defined as every second may be changed to 100 msec and 1 second according to the rotation speed when the throttle is fully closed. Further, the predetermined amount of reduction in step S602 in the dashpot amount subtraction process shown in FIG. 6 (3 [l / min] in the first embodiment) may be changed according to the rotation speed when the throttle is fully closed. Good.

Embodiment 3 In the first and second embodiments, since the correction of the intake air amount does not take into account whether the operating state of the engine 1 is no load, for example, a compressor load of an air conditioner is connected to the engine, and the load is corrected. Is driven by the engine 1,
The deceleration of the engine speed after the throttle valve is fully closed is greater than when there is no load.

Therefore, when the intake air amount is corrected in the configurations of the first and second embodiments without considering the load connected to the engine 1, the engine speed may be lower than the target speed. is there. In response to such a phenomenon, the operation signals of the load detecting means, for example, the compressor of the air conditioner are transmitted to the microcomputer 100 of the electronic control unit 19 shown in FIGS. Third input interface 103, input port 2
By inputting the signal through 04, the intake air correction amount can be switched according to the operation signal of the compressor.

For example, if the compressor is operating, the XQDP1 set in step S409 of the flowchart of FIG. 4 when the first-stage dashpot amount is set.
Is set as the value indicated by the characteristic of (circle a) in FIG.
If the compressor is not operating, the intake air amount can be corrected more accurately by configuring the compressor to be set as in step S409 in FIG.

In the present embodiment, the value to be changed according to the load detection is only the set value of the first-stage dashpot amount. However, the present invention sets the value to be changed to the first-stage dashpot amount. The intake air correction amount is not limited to the set value, but may be any value as long as the intake air correction amount can be increased or decreased according to the load state of the engine during the intake air amount correction.

For example, the first-stage dashpot amount holding time, the timing of the dashpot amount subtraction process, the dashpot amount subtraction amount, or the set value of the second-stage dashpot amount, the holding time, the dashpot The timing of the amount subtraction process and any one or a combination of the dashpot amount subtraction amounts may be changed.

In the present embodiment, the load detecting means is not limited to the operation signal of the air conditioner.
It is sufficient if the presence or absence of a load connected to the engine 1 can be detected. For example, a power assist execution signal of a vehicle equipped with power steering (for example, a hydraulic switch provided in a hydraulic circuit in the case of a hydraulic system, or a motor drive in the case of an electric system) Signal), a switch input signal of an electric load (for example, a headlight or a rear defogger) attached to the vehicle, or a power generation operation signal (an excitation signal of a field coil) of a generator connected to the vehicle. Can obtain the same result as described above.

When the vehicle is running, it may be determined that the engine 1 is under load operation, and the dashpot amount may be changed. A transmission that transmits / cuts off (neutral) the torque of the engine 1 to the drive wheels is provided. When the transmission is selected to be in a cutoff state, that is, when the transmission is shifted to neutral, the transmission is shifted to a position other than neutral. A switch that is turned off when the switch is turned on is provided, and a state signal of the switch is input to the CPU 200 through the third input interface circuit 103 and the input port 204.

The signal from the vehicle speed sensor 16 is monitored at predetermined timings (600 [msec]) while the OFF state signal is being input, and the signal is input from the vehicle speed sensor 16 at least once during the predetermined timing. Time, it is determined that the vehicle is running, and the set value of the dashpot amount, the holding time, the timing of the dashpot amount subtraction process, and the dashpot amount subtraction amount are changed in any one or a combination thereof as described above. Also obtains the same result as described above.

[0081]

According to the first aspect of the present invention, the intake air amount control means for adjusting the intake air amount of the internal combustion engine, and the throttle valve of the internal combustion engine has shifted from an open state to a substantially fully closed state. Full-closed detecting means for detecting the rotational speed of the internal combustion engine, the rotational speed detecting means for detecting the rotational speed of the internal combustion engine, the engine rotational speed detected by the rotational speed detecting means has been decelerated from a predetermined speed or more to a predetermined speed or less And calculating a first intake air correction amount for increasing the intake air amount at the moment when the throttle valve is detected to be substantially fully closed by the full-close detection means. A first intake air correction amount calculating means, and a second intake air correction amount calculating means for increasing the intake air amount at a moment when the rotation speed deceleration detecting means determines that the rotation speed has been reduced from the predetermined rotation speed or more to the predetermined rotation speed or less. Of the intake air correction amount A second intake air correction amount calculating means, and an intake air amount increasing means for increasing the intake air amount according to the intake air correction amount obtained by the first and second intake air correction amount calculating means. Therefore, an excellent effect is obtained that deterioration of exhaust gas, oil rise, afterburn, and the like due to excessive increase of the intake manifold negative pressure can be prevented, and the engine speed can be smoothly converged to the target speed.

According to the second aspect of the present invention, the second intake air correction amount calculating means detects the rotation speed deceleration from the moment when the full-close detecting means detects that the throttle valve is substantially fully closed. A means for calculating an air correction amount corresponding to the maximum value of the number of revolutions detected by the number of revolutions detection means before the means determines that the engine speed has decreased from the predetermined number of revolutions or more to the predetermined number of revolutions or less. Therefore, there is an effect that an accurate and appropriate intake air correction amount can be set.

According to the third aspect of the present invention, the second intake air correction amount calculating means calculates and stores a deviation of the rotational speed detected by the rotational speed detecting means at each predetermined timing, and stores the deviation. When the deceleration determining means determines that the engine speed has decelerated from a predetermined speed or more to a predetermined speed or less, an air correction amount corresponding to the memorized deviation of the speed is calculated. There is an effect that an accurate and appropriate intake air correction amount can be set by eliminating the influence of the rotation speed fluctuation.

According to the fourth aspect of the present invention, from the moment when the fully closed state detecting means detects that the throttle valve has become substantially fully closed, the second intake air correction amount calculating means performs the operation based on the rotation speed deceleration determining means. Since the air correction amount corresponding to the time until it is determined that the engine rotation speed has been reduced from the predetermined rotation speed or more to the predetermined rotation speed or less is calculated, an accurate and appropriate intake air correction amount with a simpler configuration. There is an effect that can be set.

According to the fifth aspect of the present invention, at the moment when the fully closed state detecting means detects that the throttle valve is substantially fully closed, the first intake air correction amount calculating means sets the intake air correction amount to the second. After the first predetermined value is set to 1, the first predetermined value is held for a first predetermined period, and then the first predetermined reduction amount is reduced to zero at every first predetermined timing. There is an effect that the rotation speed can be smoothly converged to the target rotation speed.

According to the sixth aspect of the present invention, the first intake air correction amount calculating means sets the first intake air correction amount calculating means at the moment when the throttle valve is detected to be substantially fully closed by the full closing detecting means.
At least one of the predetermined value, the first predetermined period, the first predetermined timing, and the first predetermined decrease amount is changed according to the rotation speed detected by the rotation speed detection means. There is an effect that the engine speed can be smoothly converged to the target engine speed.

According to the seventh aspect of the present invention, the second intake air correction amount calculating means determines that the rotation speed has been reduced from the predetermined rotation speed or more to the predetermined rotation speed or less by the rotation speed deceleration detecting means. At the moment, the intake air correction amount is set to a second predetermined value, and after maintaining the second predetermined value for a second predetermined period,
Since the second predetermined decrease amount is reduced to zero at each second predetermined timing, there is an effect that the rotation speed of the internal combustion engine can be smoothly and quickly converged to the target rotation speed in a short time.

According to the eighth aspect of the present invention, at the moment when it is determined that the rotational speed from the rotational speed deceleration detecting means has decreased from a predetermined rotational speed or more to a predetermined rotational speed or less, the second intake air correction amount The calculating means changes at least one of the second predetermined value, the second predetermined period, the second predetermined timing, and the second predetermined decrease amount according to the rotation speed detected by the rotation speed detection means. As a result, there is an effect that the rotational speed of the internal combustion engine can be smoothly and smoothly converged to the target rotational speed in a short time.

According to the ninth aspect of the present invention, there is provided a load operation determining means for determining whether the internal combustion engine is under no load operation or under load operation, and the first and second intake air correction amounts are provided. Since the calculating means changes at least one of the first and second predetermined values, the predetermined period, the predetermined timing, and the predetermined decrease amount from the determination result from the load operation determining means,
There is an effect that the number of revolutions can be smoothly reduced to the target number of revolutions even during the load operation of the vehicle.

According to the tenth aspect of the present invention, the load operation determination means includes a compressor operation signal of an air conditioner which is a load driven by the internal combustion engine, an operation signal of power steering, and an electric motor mounted on the vehicle. A signal detection function for detecting a load operation signal or an operation signal of a generator driven by the internal combustion engine; and a vehicle travel determination function for determining whether the vehicle is traveling or stopped, and providing the vehicle travel determination function. Alternatively, based on the vehicle traveling determination result by the vehicle traveling determining function, the first and second vehicle
At least one of the first and second predetermined values, the predetermined period, the predetermined timing, and the predetermined decrease amount of the intake air correction amount calculating means is changed, so that the intake air at the time of deceleration is changed according to the engine load. By setting the correction amount, there is an effect that the rotation speed can be more smoothly reduced to the target rotation speed.

According to the eleventh aspect of the present invention, the vehicle running determining function of the load driving determining means determines that the running speed of the vehicle is equal to or higher than a predetermined value and that the transmission transmits torque between the internal combustion engine and wheels. Since it is determined that the vehicle is under load operation when it is determined that the vehicle is running when the detection is performed, it is possible to smoothly reduce the rotation speed to the target rotation speed even during load operation of the vehicle. effective.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing an intake air amount control device for an internal combustion engine according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of an electronic control unit of the present invention.

FIG. 3 is a flowchart for explaining processing contents in an electronic control unit of the present invention.

FIG. 4 is a flowchart for explaining the details of a control amount calculation process for a bypass air control valve according to the present invention.

FIG. 5 is a flowchart illustrating the contents of a timer process according to the present invention.

FIG. 6 is a flowchart illustrating the content of a dashpot amount subtraction process according to the present invention.

FIG. 7 is a characteristic diagram for explaining a relationship between an engine speed maximum value and a second-stage dashpot set value according to the embodiment of the present invention;

FIG. 8 is a characteristic diagram for explaining the relationship between the maximum engine speed and the second-stage dashpot holding time according to the embodiment of the present invention;

FIG. 9 is a characteristic diagram showing a flow rate characteristic of the bypass air control valve according to the embodiment of the present invention.

FIG. 10 is a flowchart for explaining the content of a bypass air control valve driving process of the present invention.

FIG. 11 is a time chart for explaining the operation of the embodiment of the present invention.

FIG. 12 is a time chart for explaining the operation of the embodiment of the present invention;

FIG. 13 is a characteristic diagram for explaining a relationship between an engine speed maximum value and a first-stage dashpot set value according to the embodiment of the present invention.

FIG. 14 is a characteristic diagram illustrating a relationship between the maximum engine speed and the dashpot holding time of the second stage according to the embodiment of the present invention.

[Description of Signs] 1 Internal combustion engine, 6 Pressure sensor, 7 Throttle valve, 9
Idle switch, 10 bypass air control valve, 12
Crank angle sensor, 14 water temperature sensor, 19 electronic control unit.

Claims (11)

[Claims] An intake air amount control means for adjusting an intake air amount of the internal combustion engine; a full-close detection means for detecting that a throttle valve of the internal combustion engine has shifted from an open state to a substantially fully closed state; Rotation speed detection means for detecting the rotation speed of the internal combustion engine; rotation speed reduction determining means for determining that the engine rotation speed detected by the rotation speed detection device has been reduced from a predetermined rotation speed or more to a predetermined rotation speed or less. A first intake air correction amount for calculating a first intake air correction amount for increasing the intake air amount at the moment when the throttle valve is detected to be substantially fully closed by the fully closed detection means; Calculating means for calculating a second intake air correction amount for increasing the intake air amount at the moment when the rotational speed deceleration detecting means determines that the rotational speed has been reduced from the predetermined rotational speed or more to the predetermined rotational speed or less. Second suction empty Correction amount calculating means; and intake air amount increasing means for increasing an intake air amount to the internal combustion engine in accordance with the intake air correction amount obtained by the first and second intake air correction amount calculating means. An intake air amount control device for an internal combustion engine, comprising: 2. The second intake air correction amount calculating means determines a predetermined engine speed from the rotation speed deceleration determining means from the moment when the full-close detecting means detects that the throttle valve is substantially fully closed. 2. An air correction amount corresponding to a maximum value of the number of revolutions detected by the revolution number detecting means until it is determined that the speed has been reduced from the number of revolutions to the predetermined number of revolutions or less. An intake air amount control device for an internal combustion engine according to the above. 3. The second intake air correction amount calculating means calculates a deviation of the rotational speed detected by the rotational speed detecting means at every predetermined timing, stores the deviation in a storage means, and the rotational speed deceleration determining means. 2. The air correction amount according to claim 1, wherein when it is determined that the engine speed has been decelerated from a predetermined speed to a predetermined speed or less, an air correction amount corresponding to the stored difference in the speed is calculated. An intake air amount control device for an internal combustion engine. 4. The second intake air correction amount calculating means determines a predetermined engine speed from the rotation speed deceleration determination means from the moment when the full-close detection means detects that the throttle valve is substantially fully closed. 2. The intake air amount control device for an internal combustion engine according to claim 1, wherein an air correction amount corresponding to a time until it is determined that the vehicle has decelerated from the rotation speed to the predetermined rotation speed or less is calculated. 5. The first intake air correction amount calculating means,
At the moment when the throttle valve is detected to be substantially fully closed by the full-close detecting means, the intake air correction amount is set to a first predetermined value, and the first predetermined value is held for a first predetermined period. 2. The intake air amount control device for an internal combustion engine according to claim 1, wherein the control unit reduces the intake air amount to zero by a first predetermined decrease amount at every first predetermined timing. 6. The first intake air correction amount calculating means,
At least one of the first predetermined value, the first predetermined period, the first predetermined timing, and the first predetermined decrease amount is detected by the fully closed detection means as being substantially fully closed by the throttle valve. 6. The intake air amount control device for an internal combustion engine according to claim 5, wherein the controller changes the rotation speed according to the rotation speed detected by the rotation speed detection means at an instant. 7. The second intake air correction amount calculating means,
At the moment when the rotation speed deceleration detecting means determines that the rotation speed has been reduced from the predetermined rotation speed or more to the predetermined rotation speed or less, the intake air correction amount is set to a second predetermined value, and the second predetermined value is set. The intake air amount control for an internal combustion engine according to any one of claims 1 to 6, wherein, after the second predetermined period is held, the second predetermined reduction amount is reduced to zero at every second predetermined timing. apparatus. 8. The second intake air correction amount calculating means,
At least one of the second predetermined value, the second predetermined period, the second predetermined timing, and the second predetermined decrease amount is determined by the rotation speed deceleration detection means from a rotation speed of a predetermined rotation speed or more to a predetermined rotation speed. The intake air amount control device for an internal combustion engine according to any one of claims 1 to 7, wherein the speed is changed according to the rotation speed detected by the rotation speed detection means at the moment when it is determined that the vehicle speed has decreased to the following. . 9. A load operation determining means for determining whether the internal combustion engine is under no load operation or under load operation,
The first and second intake air correction amount calculation means change at least one of a first and second predetermined value, a predetermined period, a predetermined timing, and a predetermined decrease amount according to a determination result from the load operation determination means. The intake air amount control device for an internal combustion engine according to any one of claims 1 to 8, wherein: 10. The load operation determining means includes: a compressor operation signal of an air conditioner which is a load driven by the internal combustion engine; a power steering operation signal;
An electric load operation signal attached to the vehicle, a signal detection function for detecting at least one of an operation signal of a generator driven by the internal combustion engine, and whether the vehicle is running or stopped. A vehicle travel determination function for determining, and a first and second predetermined value of the first and second intake air correction amount calculating means based on the detection signal or a vehicle travel determination result by the vehicle travel determination function. , For a predetermined period,
The intake air amount control device for an internal combustion engine according to claim 9, wherein at least one of the predetermined timing and the predetermined decrease amount is changed. 11. The vehicle running determining function of the load driving determining means detects a running speed of a vehicle and detects that a transmission is transmitting or interrupting torque transmission between the internal combustion engine and wheels. 10. The internal combustion engine according to claim 9, wherein it is determined that the vehicle speed is equal to or higher than a predetermined value and that the transmission is running under load operation when torque transmission between the internal combustion engine and wheels is detected. Air flow control device.